Grab-type tool for sinking wells in the ground



March 31, 1959 A. P. JOURDAIN 2,879,974

GRAB-TYPE TOOL FOR SINKING WELLS IN THE GROUND Filed March 7, 1957 2 Sheets-Sheet 1 A. P. JOU RDA] N March 31, 1959 GRAB-TYPE TOOL FOR SINKING WELLS IN THE GROUND 2 Sheets-Sheet 2 Filed March '7, 1957 United States Patent GRAB-TYPE TOOL FOR SINKING WELLS IN THE GROUND Andr Paul Jourdain, Embourg-lez-Liege, Belgium, as-

siguor to Compagnie Internationale des Pieux Armes Fraukignoul, Societe Anonyme, Liege, Belgium Application March 7, 1957, Serial No. 644,569 Claims priority, application France March 12, 1956 Claims. (Cl. 255-65) The invention relates to a grab-type tool for sinking wells in the ground, comprising blades articulated at the lower end of the tool body and controlled by a member mounted for axial displacement in the said body in order to produce the opening and closing of the blades. The axial movements of this member can be produced by a pulley block system, or any other suitable system, for example a hydraulic or compressed air cylinder.

According to the invention, the member for controlling the blades is connected to an upwardly extending rod by a connection which prevents the relative rotation of the said member and the said rod about the axis of the latter, the said rod extending for free sliding and rotational movement through the wall of the tool body, this rod being adapted to co-operate with means capable of imparting to it a rotational movement about its axis, while taken from inside ice Fig. 4 is a diagrammatic plan view of the blades, the tool, the line I-I corresponding substantially to the sectional plane of Fig. 1.

In the example illustrated, the blades are controlled in a manner known per se by a pulley block system, the

. movable pulleys of which are mounted on a member,

- cylindrical form,

the said control member and the tool body are connected 2 by a connection formed by lugs or stops carried by one of these elements and capable of being displaced in axial slots or grooves carried by the other of these elements so as to permit the said body to be set in ment imparted to the said rod during the sinking oporation so as to permit a corresponding limited rotational movement of the said rod with respect to the said body and to form stops defining the movement in the axial direction of the lug co-operating with the said slot, each position of contact between the lug and a a stop thus corresponding to a determined position of opening of the blades.

In order to ensure the locking of the blades in the operative digging position, the invention provides for the said slot having a lateral notch at the corresponding height, the height of said notch corresponding substantially to that of the lug so as to lock the blades in this position. 1

The tool according to the invention enables a sinking operation to be carried out rapidly and efficiently, the control thereof being simple and reliable and permitting complete filling of the grab. Other features and advantages of the invention will be apparent from the description of one embodiment which is given by way of example and which will be hereinafter described by reference to the accompanying diagrammatic drawings, in which:

Fig. 1 is an axial vertical section of a tool accord-' ing to the invention in which the operation of the blades is controlled by a pulley block system. I

Fig. 2 is a transverse sectional view to a larger scale on the line 11-11 of Fig. 1.

Fig. 3 illustrates diagrammatically the connection between the tool body and the member, for controlling the blades, and

the axial displacement of which regulates the degree of opening of the blades. The use of such a control system is advantageous because it is simple and efficient.

, The tool illustrated comprises a body 1 of generally and the blades 2, which are for example three in number of which can be of any suitable construction, are pivoted to the base of the said body. As illustrated, they are advantageously designed in accordance with a prior patent application of the same applicants, being pivoted at a point close to their leading or frontal edge, in such manner that in the open position the opening of the blades increases progressively towards the frontal edge. The blades are each provided with a cutter 20 at their frontal edges.

Each blade 2 is fast with an arm 3, only one of which is shown in Fig. 1 for the sake of simplicity. Each arm 3 is articulated on a pivot 4 carried by the body 1. The arms 3 are connected to a member for controlling the operation of the blades by means of a pivoted connection which comprises for example a link 5 pivoted at 6 to the arm 3 and at 7 to a projection of a central part 8. This part 8 forms a bearing for a bolt 9, the nut 10 of which holds the part 8 and the head 11 of which is fixed to a tube 12 forming'part of the movable equipment of the said pulley block system. This enables a relative rotarymovement-of part 8 and tube 12. The tube 12 is guided in the central opening of a partition 13 fixed to the body 1 and shut-, ting off the housing for the pulley block system, so

- that there is no danger of the mechanism being soiled by the debris of the sinking operation. The said movable equipment also comprises a plate 14 and a tubular element 15 with a transverse section corresponding to that of a hollow rod 16, the lower end of which extends into the tubular element 15 and which is extended upwardly through the cover 17 of the body 1. This rod 16 co-operates with a mechanism capable of causing it to rotate about its axis. The equipment 12, 14 and 15 forms what iscalled in general terms the control member of the blades and is mounted to slide axially. in the tool body. This movable equipment is. fixed to the rod 16, for example, by means of a transverse pin (not shown) extending through the element 15 and the rod 16. In the example illustrated, the pulley block system comprises three movable pulleys 18, 20 and 22,

' supported by the said movable equipment, and two fixed extends upwardly through the rod 16 and serves for the control of the said movable equipment. A swivel 25 is connected in the cable 23 for preventing the cable from twisting while the tool is rotating.

The plate 14 is formed at its periphery with a certain number of lugs 26, for example three in the example illustrated, which each engage in an axial slot formed in an element 27 fixed to the inside wall of the body 1. When the plate 14 is rotated by the rod 16, it drives in its turn the body 1 as soon as the lugs 26 each bear against a lateral wall of the slot formed in the'corresponding element 27. The degree of opening of the blades 2 varies according to the position of the lugs in the direction of the axial length of the slots. In order to form stops in the axial direction of the tool,

, the invention provides for the formation of lateral'notchesf in the said slots so as to be able precisely to determine various positions of the blade as will be hereinafter explained, more especially by reference to Fig. 3. Fig. 1 shows diagrammatically the sinking position 2a and the fully opened position 2b for emptying purposes, the chain-dotted line on the right of the figure representing the corresponding positions of another blade, which would have been turned so as to bring it into the plane of the drawing.

The rod 16 can slide in a bearing 28 mounted for rotation in the cover 17 so that this rod and the equipment 12, 14 and 15 to which it is fixed can turn freely in this bearing and in the part 8 also forming a bearmg.

The rod 16 can be set mechanism, for example a 29 which is set in rotation by any suitable means and which has an opening of non-circular section, corresponding to the rod which is to be driven, the. said rod being adapted to slide in the plate 29 but participating in the rotation thereof.

The tool is provided with suspension means comprising for example a rod 30 which, in conjunction with the rod 16, forms a telescopic assembly for limited axial movement of the rod 16 in the downward direction. The bearing 28 is held in the cover 17 by a ring 31 fixed to the said cover. The rod 30 is provided with a flange 32 having openings 33 for suspending the tool by means of a cable. Rubber stops 34 and 35 are provided on the flange 32 and the cover 17 respectively in order to damp possibleshocks against the plate 29. The rod 30 rests on the bearing 28 until the sinking operation has progressed sufiiciently for the ring 34 to rest in rotation by any suitable well-sinking plate or table on the plate 29. Rings 36 are suspended from the latter 1 by chains or the like in order to permit the tool to be hooked thereon by means of hooks 37.

In order to obtain economical, rapid and eificient working ofthe tool, the blades must not only be capable of being completely closed for lifting the debris resulting from the sinking operation and then being completely opened in order to ensure rapid and complete emptying, but they must also be capable of being held in an operative partly open or sinking position. Furthermore, it is advantageous to be able to keep the blades in a slightly less open position in order to permit the easy descent into the hole already dug, for example, through the interior of a tube which' is lowered into the ground as the sinking of the well progresses.

During the sinking operation, the tool turns in a clockwise direction, which will be referred to as forward movement. When the tool is full and the blades have been reclosed by pulling on the cable 23,'as shown in full line in Figure 1, the lug 26 is in the position A (Fig. 3). By continuing the pulling action on the cable, the tool is lifted, since the blades 2 are in contact. The device is then sustained by the body 1, for example, by. suspending it by the hooks 37 in the rings 36, and the cable 23 is slackened so that the equipment 12, 14 and 15 and the rod 16 descend under the action of their own weight until the plate 14 comes into contact with the. partition 13, this corresponding to the maximum opening 2b of the blades and the position B of the lug 26. It will be understood that the result is ready detachment of the debris resulting from the sinking operation and a complete emptying of the grab. It is then necessary partially to re-close the blades in order to be able to lower the tool in the well again, this position corresponding to the position D of the lug. Owing to the provision of a lateral notch or an enlargement of the slot at a corresponding height in the element 27, this position can be automatically attained and then maintained during the downward movement. Actually, the operator first of all gives a slight forward turning movement to the rod 16, which brings the lug 26 to the position C. The device is thenlifted byapplying a pulling action to the cable 23 so as, to, bring. the lug to the position D. The device is then unhooked from the rings and is lowered to the bottom of the well by means of the cable 23. If'this position is suitable for the well-sinking operation, it is possible to lock the blades in this position by providing a supplementary notch or enlargement in the slot to the right of D and corresponding substantially to the height of the lug. However, it is advantageous slightly to increase the opening of the blades for the sinking operation, this in particular permitting the ground to be dug beneath the base of a tube in order to facilitate the lowering of the latter. This result is obtained by providing an enlargement of the slot at a slightly lower level in order to serve for accommodating the lug in the position E corresponding to the position 2a of the blades. The lug is brought into this position by a slight forward turning movement, the displacement being facilitated by the inclined transition between the notches. When the rotational movement is continued, it is not possiblefor the blades either to be opened or closed and the good working position is thus maintained during the sinking operation until the grab is refilled. In order to assist penetration into the ground, helical ribs 38 may be provided on the blades over a certain length, starting from the cutters 20. A reverse turning movement is then imparted to the rod 16 in order to bring the lug to the position F, in which it is sufiicient to pull on the cable 23 for first of all closing the blades (position A) and then lifting the device for the purpose of emptying it.

Itwill be understood that the construction according to the invention, due to the idle travel in the rotational direction, enables the lugs to be moved from left to right and vice versa by a simple rotational movement of. the rod 16 in the one or other direction.

Oncompletion of. the well-sinking operation, the lug in the position E can be wedged downwards in the element 27 under the action of the thrust exerted on the blades during the digging in order to cause them to penetrate into the ground, or else the lug can be wedged upwards if stones or a very hard layer tending to close the blades are encountered during the digging operation. The release of the lug from position E to position F is however carried out without any difliculty, because in spite of the wedging action, there is no danger of the entire device being driven during the reverse rotational movement, owing to the fact that the resistance offered by the blades 2 anchored in the ground is always very much higher than the friction of the lugs 26. This safety in operation is ensured by the fact that the rotation of. the tool is produced indirectly from inside by intervention of the member movable axially for the control of the blades, which member thus ensures the rotational movementv and. the opening of the blades. at the same time.

Thisresult could not be obtained if the rotation of the tool was produced by acting directly on the body 1. In this case, only the inertia of the movable equipment 12, 14 would be available for producing the displacement of the lugs 26 from left to right and vice versa in the slots or grooves ofthe elements 27, and even this inertia would be reduced. by various frictions. The movement of displacement of the lug 26 from D to B would already be uncertain, but that from E to F would frequently be impossible. The device would then remain wedged with the blades open in the tube or even below the tube, which would prevent it from being extracted and would cause damage thereto, thus interrupting the well-sinking work.

Moreover, the transmission of the sinking force by meansof the lugs 26 and slots 27 takes place close to the blades 2, which lowers the strain on the body 1 by'which this .force is transmitted.

It is. obvious that the invention is not limited to the embodiment which has been described and illustrated,

to which ,various modifications can he applied without thereby departing from the spirit of the invention.

What I claim is:

l. A grab-type tool for sinking wells in the ground, comprising a hollow tool body, blades pivoted to the lower end of the tool body and adapted for operating in an open position for drilling the ground, a lateral and an upper transverse wall included in the tool body, a rod extending for free sliding and rotational move ment through said transverse wall and having a lower end located within the tool body and an upper end located outside the tool body, means coupled to the upper end for imparting thereto a rotational movement about the axis of the rod, a control member mounted for axial displacement in the tool body and connected to said blades for producing the opening and closing thereof, said control member being fixed to the lower end of said rod, and extending transversely up to the immediate vicinity of the lateral wall of the tool body, a connection between said lateral wall and an outer part of said control member, said connection including peripherally spaced lugs and axial slots on the lateral wall and control member, the lugs permanently engaging the axial slots, each slot forming a stop a one end for the axial movement of the lug and determining the complete opening of the blades, the slot being of a length enabling the lug to reach a position corresponding to complete closure of the blades, and each slot having a local lateral enlargement of determined height and into which the lug can penetrate when said rod is rotated in the operative direction for drilling, said enlargement forming stops defining the movement in the axial direction of the lug and determining the total and partial opening of the blades respectively, a lateral side of the enlargement forming a stop for cooperating with the lug so as to set the tool body in rotation with its blades when the said rod is rotated in the operative direction for drilling.

2. A tool as claimed in claim 1, in which the upper end of said first enlargement forms a stop corresponding to the partial opening of the blades, thus permitting free descent into the well being sunk, and the said enlargement has a second local enlargement with a height substantially equal to that of the lug and the upper end of which is disposed slightly lower than that of the said first enlargement and is connected to the latter by an inclined surface, this second enlargement determining the slightly more open working position of the blades.

3. A tool as claimed in claim 1, in which the control member for the blades is formed by the movable equipment of a pulley block system positioned in the said body and controlled by a cable, one end of which is fixed to the said body and the other end of which extends upwardly through an axial hole formed in the said rod, which is fixed to the said movable equipment.

4. A tool as claimed in claim 3, in which the said movable equipment has at its lower end an axial extension guided for free sliding and rotational movement in a central hole of a lower transverse partition of the said body, which partition closes the part of the body containing the said pulley block system, the bottom end of the said extension being fixed axially but for free rotation to an element connected to the blades by pivoted connections.

5. A tool as claimed in claim 1, in which the said rod has a non-circular transverse section and is mounted for sliding movement in a hollow rod of corresponding section which is fixed for free rotation to the said body and extends with sliding movement through an opening having a corresponding section in a table by which the said rods are capable of being set in rotation.

References Cited in the file of this patent UNITED STATES PATENTS 386,397 Gampher July 17, 1888 1,916,688 Smith July 4, 1933 2,693,343 Darin et a1. Nov. 2, 1954 FOREIGN PATENTS 886,582 Germany Aug. 17, 1953 

